Mold for boxes



Sept. 14 1926.

Filed OGl.. 4. 1924 jc. J. HALL. ET AL MOLD FOR BOXES /lyNES/seszPatented Sept. 14, 1926.

UNITI-:o STATES 1,599,524 PATENT OFFICE.

CHARLES J. HALL, 0F WILKINSBURG, AND BENJAMIN J. GUIDO-E, OF FORESTHILLS,

PENNSYLVANIA, ASSIGNORS TO WESTINGHOUSE COMPANY, A CORPORATION OFPENNSYLVANIA.

ELECTRIC & MANUFACTURING MOLD FOR BOXES.

Our invention relates to a method of and an apparatus for moldingcomposite containers, more particularly containers formed of 'layers ofbrous sheet material, impregnated or otherwise treated with a binder,such as the well known phenolic condensation products.

It is among the objects of our invention to provide means for moldingcontainers of rectangular shape, which shall be simple and efhcient andconducive to the manufacture of such containers in an expedient andinexpensive manner.

It is a further object of our invention to provide means for formingcontainers of the above-designated character which shall insureuniformity of quality and of shape and dimensions and the formation oflittle or no fin on the outside surface of the'linished article.

Heretofore, there have been numerous means proposed for formingcontainers by molding, each of'which embodied some -particular form ofmold by which the material utilized might be given .the requisitepressure and the shape desired in the fin-V ished article.

The chief difficulty in the molding of composite containers isencountered in obtaining uniform pressure of the mold on the entiresurface of the article-being molded,

which is essential to produce the desired surface finish and therequisite physical characteristics in the molded material.

Our invention is directed to a device for molding containers thatprovides uniform pressure on the bottom and side walls of the moldedarticle and fully. supports these members during the molding operation,which insures extreme accuracy in the contour and dimensions thereof.

We utilize the usual matrix, of the size.

vention, which is utilized in molding contamers.

Fig. 2 is a plan view showing the complete mold utilized in practicingour invention.

F 3 is a cross-sectional view of the mold shown in Fig, 2, taken alongthe lines III-III of Fi 2, and ,Y Fig. 4 is a p an view showing amodification of the mold illustrated in Fig. 2.

Referring to Figs. 2 and 3, the device therein illustrated comprises acasing 1, which is disposed around a matrix 2 and is secured thereto byscrew bolts 8. A base plate 4 (Fig. 21 is disposed centrally of thematrix 2 at t e Abottom thereof, while a plurality of wedge-shapedpressure blocks, comprising four corner blocks 5, four side blocks 6 anda center block 7, are adapted to be disposed within said matrix.`

The center block 7 isl of inverted frustopyramidal shape and is providedwith corner notches 8, which make it possible to shorten the side blocks6 and prevent their interfering with each other durin the 'operation ofthe mold. The noto es 8 are adapted to Aengage the centrally extendingcorners of the blocks 5 to maintain aline-I ment of the respective blockmembers. The to portions of the blocks 6 and 7 are provi ed with screwholes 9 for receiving screws by means of which these blocks may bewithdrawn from the mold. Such action permits the collapse of theremaining blocks, which may thereafter be readily lifted out of thematrix.

In Fig. 4, the corner blocks 5 are notched at their central or innermostcorners to engage the corners of the inverted pyramidal center blockl 7for the same purpose as the' material is vpreformed in the shape showninl re'vent ter block and corner blocks until the topof the cen.

ter block 7 becomes level with the top faces of the other blocks and ofthe matrix, when ,the mold is in its closed position. During theapplication of the pressure on the cen- 7 and subsequently on the otherblocks 5 and 6, a substantially uniform pressure is exerted against theentire inner surface of the molded composition or material 10, whichresults in a container of uniform cross section and dimensions. Afterthe material is sufficiently cured, the mold is re moved from the press,and the molded article is removed from the matrix by first lifting thecenter block 7 4 (by means of a Suitable screw bolt, as previouslymentioned), and, subsequently, the side blocks and the corner blocks 5,after which the article may be pushed out of the matrix by means of thebase plate 4.

The mold is then ready for another charge and the operation is repeated.

It is evident from the foregoingv description of our invention that thedevice for molding containers described therein comprises a simple,eflicient and inexpensive means for manufacturing molded containers ofuniform quality and size.

. Although we have described a. specific embodiment of our invention, itwill be obvious' to those skilled in the art that variousmodifications'may be made in the details of construction, the size andproportions of the several co-operating parts and the manner ofutilizing the device without departing from the principles herein setforth. i

We claim as-our invention:

1. A mold comprising a matrix, a base plate therefor and a plurality ofpressure blocks disposed therein and adapted to exert uniform pressureon the sides and bottom of said matrix and plate.

2. A mold comprising a rectangular maf trix, a base plate therefor and aplurality of pressure blocks of wedge shape disposed therein andadapted'to exert uniform pressure on the sides and bottom of saiddmatrix and plate.

3. A mold comprising a rectangular matrix, a base plate therefor and aplurality of pressure blocks disposed therein and adapted to exertuniform pressure on the sides and bottom of said matrix and plate, saidpressure blocks having inclined faces.

4. A mold comprising a rectangular matrix, a base plate therefor and aplurality of pressure blocks adapted to co-operate with said matrix andbase plate, comprising a plurality of corner blocks and side blocks anda center block adapted to cooperatively engage said corner and sideblocks.

'5. A mold comprising a rectangular masaid blocks 1 trix, a base platetherefor and a plurality of pressure blocks adapted to co-operate withsaidmatrix and base plate, said blocks comprising a plurality of cornerblocks and side blocks, and a. center block adapted to co-operativelyengage said corner and side blocks, said blocks having inclined faces ontheir co-operating sides.

6. A mold comprising a rectangular matrix, a base plate therefor and aplurality of pressure blocks adapted to co-operate with said matrix andbase plate, said blocks comprising a plurality of corner yblocks andside blocks, and a center block adapted to cooperatively engage saidcorner` and side blocks, said blocks having inclined faces on theirco-operating sides and parallel faces on their work-engagingI sides.

7. A method of forming composite containers which comprises providing aplurality of layers of fibrous'sheet material iinpregnated with abinder, superposing said treated layers in the matrix of a mold,l disosing a plurality of wedge blocks on said layers and simultaneouslyapplying heatto said matrix and pressure to said blocks to effect auniform distribution of heat and pressure to the sides and bottom ofsaid matrix to consolidate said layers.

In testimony whereof, we have hereunto subscribed our names ber, 1924;.

cHAaLnsJnALL.

BENJAMIN J. GUDGE.

this first day of Octo-

